Oh Weather Channel, how I love thee! It’s amazing how much I know about what The Weather Channel is forecasting yet I never actually watch it due to the comments of my Facebook Fans. Many of my Facebook fans are often concerned about severe weather because TWC (The Weather Channel) uses the word “outbreak” when talking about the next storm. The fact is that severe weather events happen around the United States ALL YEAR. The important thing to decipher amid all the “gloom and doom” is WHERE that event will take place. Severe weather usually begins on the Gulf coast in the winter, moves into our area late winter/early spring and continues into the central plains by June and is up near the Canadian border by July. So yes, tornado events (maybe even small outbreaks) happen somewhere between March and July just about every week, they just don’t happen in the same place. Our next storm is a good example.
Take a look at the NAM computer model forecast maps on the left. Each is for Monday evening.
The top map is the rain forecast. The darker colors indicate heavier rain. Notice the area of light green from Oklahoma into Kansas. This area likely indicates a region of sct’d storms. Though the storms will likely produce heavy rain, b/c they’re widely sct’d, they only show up as light green on this map.
The next map is “spin near the surface & energy.” Where this value is high tornadoes are possible IF thunderstorms are also possible in the same region. The area of t-storms from the first map matches up well with an area of high spin. Notice however that the spin is less in Oklahoma than Kansas. This will likely lead to just regular severe storms in Oklahoma and a higher chance of tornadic storms in Kansas Monday evening.
The third map on the left shows upper level storms. The “red blob” over western Kansas indicates a strong upper-level storm approaching from the west. It’s actually moving SW to NE on this map. The area out ahead of the storm (circled) is a region where the air is going up the fastest. Air that moves up quickly tends to create stronger areas of rain. If it’s moving up very fast then thunderstorms are likely.
Now notice all three maps. See anything interesting? The area of sct’d storms happens to occur in the same place as the highest spin and the greatest lift. Sounds like all 3 occur in the same place, specifically eastern Kansas. THAT is where the “severe outbreak” will occur tomorrow and farther northeast from there on Tuesday. Arkansas is nowhere near where these 3 regions occur together.
Yes, we see t-storms in the summer. Though these storms are as loud as the ones in the spring, because the storm track is farther north, and these upper level storms are now tracking farther away from us, the conditions that would cause our t-storms to spin are no longer present. So even though they produce lots of lightning, thunder, wind and hail, they seldom produce tornadoes.
Yes, an isolated tornado is not out of the question. Arkansas has seen tornadoes every month of the year, but we see only a fraction of the tornadoes in the summer that we do in the spring. In fact we see more tornadoes in the month of April than June, July & August combined (in most years). Stay tuned for another post on Arkansas tornado stats and numbers coming soon.
Greg “Weather Dork” Dee